The scientific goal of this project is to investigate the role of relative growth hormone (GH) deficiency in the etiopathology of bone loss in obese men and women, and the mechanisms by which GH may affect bone microarchitecture and strength. The candidate is an Associate Professor of Medicine at Harvard Medical School and a faculty member at Massachusetts General Hospital who is deeply committed to and highly qualified for a career in patient-oriented research and to mentor new clinician investigators. She has an outstanding record of patient-oriented research (POR) and mentoring during the first K24 grant period. The career development goal of this K24 competitive renewal application is to support the candidate's continued professional development as a POR mentor of fellows and junior faculty with her long-term goal of developing independent POR researchers. The candidate's specific short-term mentoring objectives are: 1) to attract and train new trainees, 2) assist her current mentees to obtain K and R grant funding, to develop their own POR focuses and assist with all other aspects of transitioning to independent careers focused on POR, 3) acquire additional mentoring skills and 3) continue and expand teaching in courses that reach a large number of trainees interested in pursuing POR careers. The candidate's NIH grants will form the basis of research project support for trainees. The candidate has a record of leadership in mentoring on a national level and a successful track record of mentoring trainees in the Massachusetts General Hospital (MGH) Endocrine Fellowship program and trainees from a number of other departments. The institutional environment is outstanding at the MGH and Harvard Medical School, with an extremely strong Department of Medicine, a Clinical Translational Science Center grant through Harvard Medical School, and a Clinical Research Program at the MGH, all of which offer a myriad of didactic opportunities, facilities and support. The Department of Medicine has made a strong commitment to the candidate, including protected time and dedicated space. The Midcareer Investigator Award in Patient-Oriented Research is an ideal mechanism to ensure the necessary support to protect time for mentorship for this outstanding mentor, who otherwise would have to increase her clinical and administrative responsibilities, and to ensure the candidate's continued success as a mentor and clinical researcher.